Lab 1
Level 1 - Beginner
Local Storage Secret Leak Lab
Level 1 Client-Side Security simulation: learn why storing authentication secrets in localStorage increases frontend exposure risk.
Beginner
Client-Side Security • 20 min
Learning Objectives
This lab is a controlled simulation only. No real backend or dangerous code execution is used.
Objective 1
Review a fake browser storage viewer and identify which key represents sensitive authentication data.
Objective 2
Understand why browser-accessible secrets become especially risky when XSS or other frontend compromise is present.
Objective 3
Learn why reducing token exposure and choosing safer storage patterns matters in modern web apps.
Challenge Area
Use the input fields below to safely simulate the vulnerable behavior.
Sensitive Storage Key
Fake localStorage Viewer
theme=dark
lang=en
auth_token=abc123-demo-token
Submitted key: (none yet)
Result Panel
Review the fake localStorage entries and enter the key that represents the sensitive authentication secret in this simulation.
Hints
Reveal them progressively if you get stuck.
Click the hint button to reveal progressive guidance.